To systematically evaluate the insulin deficiency and insulin resistance which characterize a unique phenotype of diabetes mellitus, evident in a high proportion of young Afican Americans in South Carolina. The syndrome, a ketosis-prone form of NIDDM referred to as Atypical Diabetes Mellitus, has not been well described in the medical literature. To delineate the progression and evolution of metabolic abnormalities which results in ADM. Attention will be focused upon the insulin resistant state induced by growth hormone excess in the adolescent and young adult populations. Elucidation of the role of growth hormone in ADM may result in novel therapies (e.g., IGF-I, Octreotide) for this and other forms of diabetes. Since ADM represents a subset of NIDDM with strong familial tendencies, we will seek to identify genetic variations associated with ADM. Due to proven association between insulin deficiency and a defect in glucokinase, we will test ADM families for mutations in this gene. A number of other logical candidate genes (e.g. GLUT 2, Insulin) will be also tested.